Silicon (Si) or silicon-based substrates are frequently employed for manufacturing integrated circuits (ICs). A monocrystalline silicon substrate has a uniform lattice structure. As used in IC manufacturing, the Si substrate is typically in the form of a thin circular wafer, cut from an ingot, and varying from 100 mm to 300 mm in diameter (although both smaller and larger diameters, as well as other geometries are also used). Additionally, elemental semiconductor types other than silicon are frequently used in manufacturing ICs as well. These other elemental semiconductors, such as germanium, are materials contained in Group IV of the periodic chart. Further, compound semiconductors (e.g., compounds of elements, especially elements from periodic table Groups III-V and II-VI) have seen increased IC manufacturing activity in recent years. Compound semiconductors are frequently used for manufacturing ICs used in, for example, high-speed signal processing applications. Semiconducting alloys (e.g., AlxGa1-xAs, HG1-xCDxTe) are also becoming more common in ICs. Additionally, non-semiconducting materials such as, for example, a polyethylene-terephthalate (PET) substrate deposited with silicon dioxide or a quartz photomask, each of which may be deposited with polysilicon followed by an excimer laser annealing (ELA) anneal step may also be used in certain applications for ICs and related electrical structures.
However, regardless of the substrate employed in manufacturing ICs, integrity of the substrate structure is essential in order to maximize the yield for the ICs manufactured on the substrate. Current techniques to determine structural defects within substrates include Scanning of Infrared Depolarization (SIRD) and a combination of photoluminescence and photo-thermal heterodyne spectroscopy combined with SIRD. While these techniques are able to characterize explicit crystal defects including dislocations, cracks, scratches, and foreign particulates, each of these techniques involve complex and costly test equipment that require the substrate to be analyzed offline. Offline analysis either significantly delays the overall process time of the substrate or provides results of the substrate integrity only after the substrate has been fully processed. Regardless, offline analysis is time-consuming and costly in any manufacturing or fabrication process line.